376 



h. m. s. 

 Brought forward, +0 01 06.54 



Reduction to the steeple of the Roman Catholic 



Church on Jackson street, Milwaukee, - — 0.21 



Steeple of the Roman Catholic Church, Milwaukee, 



west of the Chicago observing station No. 3, + 01 06.33 



Longitude of Chicago station No. 3, west of the me- 

 ridian of Greenwich, - - - - -j- 5 50 31.2 



Determination 2d. 



Longitude of the steeple of the Roman Catholic 

 Church on Jackson street, Milwaukee, west of 

 the meridian of Greenwich, - - - 5 51 37.53 



My duties detained me at Milwaukee until the afternoon rail road 

 train of July 3d. The night of the 2d was cloudy, and part of it 

 rainy, and not a star could be seen. 



The od was clear, so I determined to try the result of a third se- 

 ries of telegraphic signals for the difference of longitude between the 

 two places, which should rest for the Milwaukee time, on a set of equal 

 altitudes of the sun observed with the sextant and artificial horizon, 

 A. M. and P. M. The signals were passed by telegraph between the 

 periods of the forenoon and afternoon observations. 



I could not observe in the day time, either in the court house yard, 

 or at station No. 1 of June 23d, because there were so many carri- 

 ages, drays and persons on foot, constantly passing near by, that the 

 artificial horizon of quicksilver was, I found while at those stations 

 during the day, kept constantly agitated. 



I was obliged therefore, to seek a more quiet position than either 

 of those two. This I found in a vacant lot at the north east corner 

 of Jackson and Martin streets. 



The position here occupied I call Milwaukee Station No. 3. It is 

 890 feet north of the parallel, and 38 feet east of the meridian of the 

 steeple before mentioned. Hence the reduction from this station No. 

 3, to the said steeple is — 8". 8 in latitude, and + 0".512 of arc = 

 -f 0s.034 of time, in longitude. 



The equal altitudes of the sun we accordingly observed as follows, 

 viz: 



